In the wake of a series of embarrassing hidden-camera exposes and mounting congressional pressure to cut off its federal funding, ACORN announced on Wednesday it would immediately stop accepting new clients at its offices across the country.

Bertha Lewis, CEO of the embattled community organizing group, also said the Association of Community Organizations for Reform Now would name an independent auditor and investigator to conduct a wide-ranging review of the organization.

“As a result of the indefensible action of a handful of our employees,” Lewis said in a statement, “I am, in consultation with ACORN’s Executive Committee, immediately ordering a halt to any new intakes into ACORN’s service programs until completion of an independent review.”

The drastic step effectively puts an end to ACORN’s extensive service programs for new clients, including counseling for low and middle-income home buyers and tax preparation at its offices in 75 cities across the country. ACORN officials have also ordered its staff in those local branches to receive additional training within 48 hours.

In recent days, Republican congressional leaders have led an effort to slash the funding ACORN receives from government agencies. On Tuesday, House Minority Leader John Boehner (R-Ohio) and other top Republicans called on President Barack Obama to use his executive authority to ban to all federal agencies from providing money to support ACORN’s programs. That move came on the heels of a Senate vote a day earlier to bar the Departments of Transportation and Housing and Urban Development from issuing any new federal grants to the organization.

The controversy surrounding ACORN escalated in the wake of the release of series of undercover videos that showed employees of the organization and an affiliate group providing advice on how to falsify tax forms and set-up a child prostitution business to two conservative activists dressed up as a prostitute and her pimp.

In her statement on Wednesday, Lewis said she was “deeply disturbed by what we’ve seen in some of these videos.” Four employees of ACORN and ACORN Housing Corporation who appear on the tapes have since been fired.

Lewis noted that she would be assisted by ACORN’s advisory council in choosing an outside auditor, who she said would be named no later than Sept. 18.

The advisory council includes John Podesta, head of the Center for American Progress, a liberal think tank; Andrew Stern, president of the Service Employees International Union; and former Maryland Lt. Gov. Kathleen Kennedy Townsend.

“ACORN has a long history of serving those who most need help, and giving voice to those who have been left behind.” Townsend said in a statement. “We will take the necessary steps to ensure that ACORN functions with the highest levels of ethical standards and competence.”

Lewis said that group was committed to implementing all the recommendations of the independent auditor.

But Michael Steel, a spokesman for Boehner, said the steps ACORN announced on Wednesday were “too little, too late.”

“Given that the latest embarrassing abuses occurred after this independent Advisory Council was established, I’d say ACORN has little — if any — credibility when it comes to policing itself,” Steel said.